Refrigerating system



June 12, 1928.

A. S. LEWIS REFRIGERATING SYSTEM Fild u s. 1920 2 Sheets-Sheet 1 June 12, 1928.

A. s. LEWIS REFRIGERATING SYSTEM Filed Aug. 1920 2 Sheets-Sheet Patented June 12, 1928.

UNITED STATES 1,673,082 PATENT OFFICE.

ALFRED S. LEWIS, OF WEST CHESTER, PENNSYLVANIA, ASSIGNOR TO THE MOTOR- FRIGERATOR COMPANY, OF WEST CHESTER, PENNSYLVANIA.

REFRIGEBATING SYSTEM.

This invention relates to improvements in refrigerating systems of the direct expansion type,one object of the invention being to provide a simple refrigerating apparatus which may be air-cooled and easlly controlled; which can be built at the factory ready for installation in a refrigerator box; which may be sold at a moderate price and which may be operated at a low cost.

A further object is to improve and simplify the construction of the compressor constituting an important element of the system.

l/Vith these and other objects in view, the invention consists in certain novel features 1 of construction and combinations of parts as hereinafter set forth and pointed out in the claims.

In the accompanying drawings; Figure 1 is a view illustrating the installation of the apparatus in a refrigerator box or casing;

Figure 2 is a sectional view (partly in elevation) taken at right angles to Figure 1; Figure 3 is a plan view of the compressor; Figure 4 is a view partly in section and partly in elevation, illustrating the compressor; Figure 5 is a transverse sectlonal view of the compressor, and Figure 6 is a separate view, partly in section, of the compressor piston and operating means therefor.

1 represents a refrigerator box or cas ng having a compartment 2 in its lower portion in which the operating unit 3 is located, and having in its upper portion, a pan 4 on which the refrigerating unit 5 is supported. The pan 4 serves to receive any condensation which might be formed on the refrigerating unit and it is connected by a drip pipe 6 with an open trap 7 located in the compart ment 2 containing the operating unit, the

heat from which will serve to evaporate any water which may reach said trap.

It will be observed that with my improved construction, the air in chamber 2 moistened by the evaporation of the drip water collecting in the trap 7, will be forcibly expelled by means of a draft upwardly through aflue 12 The refrigerating unit comprises an expansion coil 8 and an expansion valve 9, while the operating unit comprises a compressor 10, an electric motor 11 for operating the same, and a condenser 12. The air for cooling the motor, compressor and condenser, enters at 12 and passes out through the flue 12.

Application filed August 9, 1920. Serial No. 402,113.-

The expansion valve 9 is connected, on the pressure side of the apparatus, by a pipe 13 with the discharge valve 14 at the base of the condenser 12 and this pipe is provided with a charglng intake 15 for the refrigerant, such as ethyl chloride, and said intake is provided with a valve 16. The expansion coil 8 is connected with the vacuum side of the expansion valve and a pipe 17 connects the expansion coil to the intake part l8'of the compressor. The discharge port 19 of the com pressor is connected by a pipe 20 (having a valve 21) with the condenser 12.

The compressor 10 is of the double acting type and comprises a cylinder 22 provided at its respective ends with heads 2323 and each of these heads is made with two valve chambers 24 and 25, all of which are adapted to communicate with the interior of the cylinder. The valve chambers 24 are connected by a duct 26 with the inlet port 18 of the compressor, and the valve chambers 25 are connected by a duct 27 with the interior of the cylinder midway between the ends thereof. An inlet valve 28 is provided for the port of each valve chamber 24, and each of said valves may be made in the form of a headed rod passing through a bushing 29 and normally held in position to close communication with the interior or compression chamber of the cylinder, by the action of a spring 30. An outlet valve 31 (which may be made tubular in form having one end closed) is provided to control communication between the interior or pressure chamber at each end of'the cylinder and the duct 27 and each valve 31 is held normally closed by a spring 32.

A double-acting piston 33 is located to re ciprocate in the cylinder 22 and is provided near its respective ends with suitable packing indicated at 34. The intermediate diate portion of the piston is also made with an elongated opening 39 in which a cross head 40 is adapted to reciprocate, said cross? head having a central opening for the accommodation of a cam or eccentric 41 carried by the shaft 36, and the ends of said cross head may be rounded to move on similarly shaped ways 42 in the piston at respective sides of the elongated opening 39. It is apparent that with the construction and arrangement of parts above described, rotation of the shaft will cause the dOublB-actiIlg piston to reciprocate within the cylinder of the compressor. It will also be seen that the construction of the piston is such that a passage will be provided transversely through it which will serve as a duct for fluid from the duct 27 to the-discharge port 19 of the compressor.

When the units comprising the refrigerating system shall have been assembled as shown in Figures 1 and 2 of the drawings and air has been exhausted from the systemand a charge of ethyl chloride or other refrigerant has been placed in the condenser together with a charge of lubricant (such as glycerine for example), the operation of the system will be as follows The normal pressure of the ethyl chloride will cause the fluid to rise in the pipe 13 to the expansion valve, which latter is held in closed position by its spring, while the compressor is at rest. The first action of the compressor, when in operation, will be to create a vacuum in the low pressure side of the system, through pipe 17, expansion coil 8 and chamber of the expansion valve 9. When the pressure reaches fifteen inches, the expansion valve will open, allowing a very small quantity of fluid to pass and this will be rapidly converted into a gas in the vacuum, absorbing heat units as it passes throughthe expansion coil 8 and throu h the pipe 17 to the compressor. After the gas passes through the compressor, it is orced by the latter into the condenser 12, where the heat is absorbed by air circulation about the coils of the condenser, causing the gas to be condensed to a liquid and thus completing a cycle of operations. This cycle of operations will be continued until sufficient heat units shall have been absorbed from the food chamber of the refrigerator to reduce the temperature to the desired degree, when a thermostat in said chamber will operate aswitch in the motor circuit and thus stop the motor. When the temperature in the food chamber again rises, the thermostat will operate the switch to start the motor and reestablish the cycle of operations previously described.

In using a refrigerant such as ethyl chloride, which requires a deep vacuum in order to obtain the full refrigerating effect, there is a tendency to draw air into the system through the stuffing box on the compressor, but I overcome this by placing the stuffing box on the pressure side of the system.

The compressor is so designed that the lubricant, which is carricd,with the refrigerant, lubricates all internal moving parts, thus insuring the system to be always hermetically sealed.

In the operation of the compressor, the gases and lubricant enter at the intake part 18 and after passing through the duct 26, will be drawn past the valves 28 alternately into the compression chambers of the cylinder, from which they will be subsequently forced and caused to flow past the valves 31 to the duct 27 and conducted by the latter to an intermediate portion of the cylinder and discharged through the central portion of the double acting piston to the discharge port 19.

Various changes might be'made in the details of construction of my invention without departing from the spirit thereof or limiting its scope and hence I do not wish to restrict myself to the precise details herein set forth.'"'--- Y Having fully described my invention what I claim as new and desire to secure by Letters-Patent, is 2-- 1. In a refrigerator having cooling coils disposed within its refrigerating chamber, a moisture collecting pan disposed for collecting moisture condensed on the cooling coil, means for feeding the condensed moisture out of the refrigerating chamber into a lower portion of the refrigerator, and means for thereafter causing air outside of the re frigerating chamber to absorb the said moisture and for expelling the resulting moistened air from the refrigerator.

2. The method of reducing'the moisture content of the air in the refrigerating chamber of a refrigerator, which consists in condensing moisture from the air on a chilled surface within the said chamber, conducting the condensed moisture out of the cham ber, causing air drawn from outside the refrigerator to absorb the condensed moisture, and forcibly expelling the thus moistened air from the refrigerator.

In testimony whereof, I have signed this specification.

ALFRED S. LEWIS. 

